Filter-plate.



No. 886,464. PATENTED' MM5, 190e.

. 3H. M. ASHBY.

FILTER PLATE.

APPLICATION FILED DEO. 24, 1906.

MW y Mu 1HE Nanni: PETERS cn.. wAsHlNm'oN. U. c.

IINI'ID STATS AT FICE.

HOLDON M. ASHBY, OF CHICAGO, ILLINOIS.

Application filed December 24, 1906.

have invented a new and useful Improve-V ment in Filter-Plates, of whichthe following is a specification, the principle of the invention beingherein explained and the best mode in which I have contemplated applyingthat principle -so as to distinguish it from other inventions.

My invention relates to an improvement in filter presses and hasparticular regard to the construction of filter plates for use therein.

The object of such invention is to provide a filter press plate thatwill combine in itself the desirable qualities of durability efficiencyand inexpensiveness.

To this end said invention consists of means hereinafter fully describedand particularly set forth in the claims.

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed means,however, constituting but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexed drawing: Figure l is a plan view of a filter plateembodying my several improvements; Fig. is a transverse cross-section ofthe same on the line 2-2, Fig. l; Fig. 3 is an end elevation of suchplate; and Fig. 4 is a transverse cross-section at right angles to thatappearing in Fig. 2, being taken on the line 4%, Fig. 1.

Atpresent there are two types of filter plates on the market, therecessed filter plate and the flat plate which in use is alternated withhollow rings. It should be stated that it is to the former of these twotypes that my present invention pertains. lSuch recessed style of platehas heretofore been made in two styles, either of cast iron or of wood.An objection to the use of the former material in the construction ofthe plates arises from the fact that it is apt to prove brittle,especially where the corrugations cut into it, as they must, quitedeeply, and, furthermore, in handling certain materials, the iron isinclined to rust whereby the thin sheet forming the plate proper isquickly destroyed and the plate so rendered useless. The objection tothe wooden plate is that, being constructed wholly of wood, it is apt toprove weak at the joints and, hence, will give way under any except arelatively low pressure.

Specification of Letters Patent.

Patented May 5, 1908.

Serial No. 349,258.

In fact, numerous trials have demonstrated that it cannot be safely usedto stand over twenty pounds pressure.

The plate which I have devised as a substitute for both the precedino`structures comprises as its base the filter pIate, proper, A, which, inthe particular structure chosen for the sake of illustrating myinvention, is of rectangular or substantially square form. It will, ofcourse, be understood that any variation in this form is immaterial,.since the latter depends wholly u on the form of the machine in whichthe p ates are being used.

VThis filter plate proper consists of an integral wooden sheet A of theproper thickness, and with the usual water channels a grooved into itsfaces, giving the board in cross-section the corrugated ap earance shownin Fig. 2. This Wooden s eet A is then clamped between two complementaryrigid frames A.

Frame A I preferably make in the form of an iron or steel casting, andthese castings are riveted together so as to tightly clamp the woodsheet therebetween by means of rivets a2 or equivalent devices. In orderto insure a tight joint between the wooden sheet A and the frames, alayer of cement or like material is used. The outer faces of the framesare furthermore provided with a felt gasket o4 cemented thereon by meansof rub ber cement, or the like, whereby the joints between successiveplates, when mounted in the press, are made tight. The wooden sheet Ais, of course, provided with suitable holes, as a', for the escape ofthe expressed liquid.

Having thus described the construction of my plate, it is not deemednecessary to set up in detail the manner of its use, such being wellunderstood. I should, however, call attention to the superior qualitiespresented by such filter late when in use over the older forms of p atesto which reference has been made.- The castings forming the framebetween which the wooden sheet is clam ed are made sufficiently strongto give rigidity to the latter and prevent all sidewise warpingAthereof. They so provide a rigid support to which the top and bottom ofthe plate are attached. As a result of this construction, the plate isput under tension, as it were, and the strain towhich it is subjected inactual use affects only the tensile strength of the wood fibers. This isobviously not the case in the ordinary wooden plate, Where the stren thof the joints between the edges of the p ate proper and the frame is thelimit of the strength of the whole plate. The plate is racticallyindestructible since wood, as is welll known, is least affected of allordinary materials by the liquids usually met with in the use of'filterpresses. The action of such liquids, while frequently causing the rapidcorrosion of the thin metallic or iron plate has, as has been stated,only a relatively slow action on the heavy rim or frame, so that thelatter is not particularly injured even where of iron. Furthermore, theplate can be produced at a much lower cost than can any of the otherplates above described. This for the reason that, by using wood incombination with the metal, it is made possible to do away with anymachining or finishing of the surface of the metal, the wood beingsufficiently soft to take u any inequalities of the latter. Such inequaities, as far as a tight junction between adjoining plates in theassembled press is concerned, are, of course, taken care of by the feltgaskets. It will be understood that other material than wood,

such, for instance, as hard rubber, papiermch, Celluloid, or the like,may be substituted for the same in the construction of the plate, wherefor any reason these other materials may prove more desirable. Likewisethe frame, instead of being in the form of a metallic casting, may bestamped out of sheet metal, a method of manufacture that will stillfurther decrease the cost.

Having thus described my invention in detail, that which I particularlypoint out and distinctly claim, is:

l. In a device of the character described, the combination with a rigidinflexible metallic frameJ of a nonmetallie filter plate proper firmlysecured to said frame so as to be maintained in a state of tension.

2. In a device of theA character described, the combination with a rigidinflexible metallic frame, of a filter plate proper consisting of anintegral sheet of fibrous material firmly secured to said frame wherebythe fibers thereof are maintained in a state of tension.

3. In a device of the character described, the combination with aV rigidinfiexibleframe, of a filter plate proper consisting of an integralsheet firmly secured about its entire periphery to said frame so as tobe maintained in a state of tension.

4. In a device of the character described, the combination with a rigidinflexible meperiphery, whereby the fibers thereof are maintained undertension.

6. In a device of the character described, the combination with a filterplate proper consisting of an integral wooden sheet, of two rigidmetallic frames, the edges of said sheet being firmly clamped betweensaid frames, whereby the fibers thereof are maintained under tension. j

7. In a device of the character described, the combination with a filterplate proper Vconsisting of an integral wooden sheet, of j two rigidmetallic frames, the edges of said sheet being clamped between saidframes and the latter being firmly riveted together whereby a tightjoint is 4formed and the fibers of said sheet maintained under tension.

8. In a device of the character described,

the combination with a filter plate roper consisting of an integralwooden sheet iaving its faces channeled, of two cast iron frames', theedges of said sheet being firmly clamped between said frames whereby atight joint is formed.

9. In a device of the character described, the combination of a filterplate proper consisting of an integral wooden sheet having its faceschanneled and being provided with suitable apertures for the escape ofthe eX- pressed. liquid; two complementary cast-iron frames, the edgesof sald sheet bein firmly clamped between said frames and a ayer ofcement being interposedbetween said sheet and said frames, respectively,whereby a tight joint is formed g and a felt gasket cemented on theouter face of each of said frames.

Signed by me, this 19th day of December 1906.

HOLDON M. ASHBY.

Attested by- HENRY PETERSON, J. L. Mouais.

